Octadienylamines are used, for example, as intermediates for the preparation of octylamines, which in turn are required, for example, for the preparation of fabric softeners, corrosion inhibitors, flotation auxiliaries and emulsifiers. For these purposes, octa-2,7-dienyl-1-amine in particular is of interest.
In the telomerization of butadiene and ammonia, complex reaction mixtures are usually produced which, in addition to octa-2,7-dienyl-1-amine, contain considerable amounts of octa-1,7-dienyl-3-amine and secondary and tertiary octadienylamines.
From EP-A 773 211, it is known to carry out the telomerization of butadiene and ammonia in a two-phase system and to use as catalysts mixtures of palladium compounds and phosphors compounds which improve the solubility of the palladium compounds in water, for example sulphonated triphenylphosphines.
Reaction mixtures containing octa-2,7-dienyl-1-amine (1), octa-1,7-dienyl-3-amine (2) and secondary octadienylamines (3) are produced. (1) forms in selectivities of from 40 to 56%, (2) in selectivities of from 28 to 43% and (3) in selectivities of up to 10%. The reaction mixtures were not worked up.
According to EP-A 816 308, the complex compounds used as catalysts for said telomerization contain, as central atom, a transition metal and at least one tris(hydroxyalkyl)-phosphine or -phosphine oxide as ligand. For butadiene conversions of from 4 to 63%, the selectivity of the formation of (1) can be increased to 66%, and for butadiene conversions below 2% (i.e. large butadiene excesses) up to as much as 85%. The selectivity of the formation of (2) is in the range from 1 to 40%, there being no direct relation of selectivities of the formation of (1) and (2). For example, (2) is obtained with a selectivity of 9% when (1) is produced with a selectivity of 85%, and a selectivity of 1% when (1) is formed with a selectivity of 55%. The reaction mixtures are not worked up here either.
There is therefore a continued need for a process for preparing octa-2,7-dienyl-1-amine in good selectivities and yields as far as possible irrespective of the catalysts, butadiene excesses and other parameters used.